Squashed commit of the following:

commit 10456b1e9240886432f565dd17689080bbb133b9
Merge: 312c1a9bdf8 a5f4627857b
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Thu Nov 29 14:33:21 2018 +0900

    Merge branch 'master-ce' into add-counter-for-trace-chunks

commit 312c1a9bdf8efc45c3fed5ff50f05cc589bbb4ed
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Wed Nov 28 20:06:18 2018 +0900

    Fix coding offence

commit e397cc2ccc1b2cf7f8b3558b8fa81fe2aa0ab366
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Wed Nov 28 14:40:24 2018 +0900

    Fix tracking archive failure

3 files changed, 27 insertions, 14 deletions

diff --git a/app/services/ci/archive_trace_service.rb b/app/services/ci/archive_trace_service.rb
new file mode 100644
index 00000000000..8504ceb2327
--- /dev/null
+++ b/app/services/ci/archive_trace_service.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module Ci
+  class ArchiveTraceService
+    def execute(job)
+      job.trace.archive!
+    rescue ::Gitlab::Ci::Trace::AlreadyArchivedError
+      # It's already archived, thus we can safely ignore this exception.
+    rescue => e
+      archive_error(e, job)
+    end
+
+    private
+
+    def failed_archive_counter
+      @failed_archive_counter ||= Gitlab::Metrics.counter(:job_trace_archive_failed_total, "Counter of failed attempts of trace archiving")
+    end
+
+    def archive_error(error, job)
+      failed_archive_counter.increment
+      Gitlab::Sentry.track_exception(error, issue_url: 'https://gitlab.com/gitlab-org/gitlab-ce/issues/51502', extra: { job_id: job.id })
+      Rails.logger.error "Failed to archive trace. id: #{job.id} message: #{error.message}"
+    end
+  end
+end
diff --git a/app/workers/archive_trace_worker.rb b/app/workers/archive_trace_worker.rb
index c1283e9b2fc..4a9becf0ca7 100644
--- a/app/workers/archive_trace_worker.rb
+++ b/app/workers/archive_trace_worker.rb
@@ -7,7 +7,7 @@ class ArchiveTraceWorker
   # rubocop: disable CodeReuse/ActiveRecord
   def perform(job_id)
     Ci::Build.without_archived_trace.find_by(id: job_id).try do |job|
-      job.trace.archive!
+      Ci::ArchiveTraceService.new.execute(job)
     end
   end
   # rubocop: enable CodeReuse/ActiveRecord
diff --git a/app/workers/ci/archive_traces_cron_worker.rb b/app/workers/ci/archive_traces_cron_worker.rb
index 7443aad1380..f65ff239866 100644
--- a/app/workers/ci/archive_traces_cron_worker.rb
+++ b/app/workers/ci/archive_traces_cron_worker.rb
@@ -11,21 +11,9 @@ module Ci
       # This could happen when ArchiveTraceWorker sidekiq jobs were lost by receiving SIGKILL
       # More details in https://gitlab.com/gitlab-org/gitlab-ce/issues/36791
       Ci::Build.finished.with_live_trace.find_each(batch_size: 100) do |build|
-        begin
-          build.trace.archive!
-        rescue ::Gitlab::Ci::Trace::AlreadyArchivedError
-        rescue => e
-          failed_archive_counter.increment
-          Rails.logger.error "Failed to archive stale live trace. id: #{build.id} message: #{e.message}"
-        end
+        Ci::ArchiveTraceService.new.execute(build)
       end
     end
     # rubocop: enable CodeReuse/ActiveRecord
-
-    private
-
-    def failed_archive_counter
-      @failed_archive_counter ||= Gitlab::Metrics.counter(:job_trace_archive_failed_total, "Counter of failed attempts of traces archiving")
-    end
   end
 end